Open grip-handle, inside-trigger pneumatic tool.



' M. 1. BURKEL.

OPEN GRIP HANDLE, INSIDE TRIGGER PNEUMATIC TUOI..

APPLICATION FILED FEB. 12. 1916.

1,238,255. PatentedAug. 28,1917.

'TTF STATES FATET FFTQE.

MATHEW J. BURKEL, OF AURORA, ILLINOS.

OPEN GRIP-HANDLE, INSIDE-TRIGGER PNEUMATIC TOOL.

Application led February 12, 1916.

To all whom t may concern:

Be it known that I, MATHEW J. BURKEL, a citizen of the United States,and a resident of Aurora, in the county of Kane and State of Illinois,have invented certain new and useful Improvements in Open Gripandles,Inside-Trigger Pneumatic Tools; and I do hereby declare that thefollowing is a full, clear, and exact description thereof, referencebeing had to the accompanying drawings, and to the letters of Vreferencemarked thereon, which form a part of this specication.

This invention relates to improvements in open grip handle, insidetrigger pneumatic tools. The invention consists of the mattershereinafter described and more particularly pointed out in the appendedclaims.

The object of the invention is to provide an open grip handle, having aninside trigger for controlling the admission of the pneumatic duid,together with a valve mechanism so arranged in the head that the handleand head may be made in a commercially practicable manner. The manyadvantages of the invention will appear as T proceed with myspecification.

Referring to the drawings:

Figure 1 is a view representing a longitudinal section of a pneumatichammer having an open grip handle provided with my improved insidetrigger and admission valve.

Fig. 2 is a view representing a partial section through Fig. 1 in aplane indicated by the line 2 2 of Fig. 1.

Fig. 3 is a perspective view of the trigger.

Referring now to that embodiment of my invention illustrated in thedrawings, 10 indicates the body of a pneumatic tool, in this case thebarrel of a pneumatic hammer; 11 indicates the piston or hammerlongitudinally reciprocable therein; 12 indicates the tool at the end ofthe barrel; 13 indicates the head that closes the upper end of thebarrel; and 14 indicates the operating valve mechanism` (inclosed by thehead) which with the inlet and exhaust passages and ports in the barreland head control the inlet and exhaust of the pneumatic fluid in suchmanner as to produce the reciprocation of the piston hammer in thebarrel to operate upon the tool in a familiar manner.

The head proper 13 is of the usual form .but is provided with an openhandle 15 made tubular to provide a passageway ,1,6 for theSpecification of Letters Patent.

Patented Ane. 28, 1917.

Serial No. 77,816.

admission of the pneumatic fluid. The handle 15 is fabricated integrallywith the head and is in the form of a prolongation 16L of one end of aboss 16b on the end wall 13 of the head and extending transversely ofsaid end wall. The head with the handle extension 16a may be made as adrop forging, with the boss extension 16a in line with the boss 1Gb sothat the extension may 'oe t bored, before bending the handle, from oneend to produce the passageway 16 and may be bored from the opposite endto produce opening 16C that is to contain the casing or bushing for theadmission valve now to be 13a of the head for the supply of thepneumatic fluid to the operating valve 11. The valve bushing 17 has anannular groove in line with the port 18 which provides an annular space19 about said bushing and communicating with said port. Annular spacedports Q0 connect the interior of the casing with the annular space 19. Y

21 indicates a piston valve plug which is adapted to reciprocate in thebushing 17 and to coact with the ports :2O therein. Said valve isnormally closed on the ports 2O and as shown, is spring controlled,-aspring 22 being interposed between the valve and a plug 23 which isthreaded into the outer end of the bushing 17 to close the valvechamber. Both the valve plug and the closing `plug' 23 are provided withsuitable recesses to'seat the ends of the spring Q2. The valve 21 has astem 24 which is fixed to a head piece 25 that has sliding bearing inthe valve l casing. Said head piece is operatively engaged by a trigger26 that is fulcrumed to swing in the plane of the handle. Sait triggeris fulcrumed between spaced lugs 27 27 made integral with the handle andi recess 28 and in planes parallel thereto. Said channels connect thepassages 16 of the handle with the interior of the valve casing.

The trigger 26 has an operating arm 26b which is curved in a mannersimilar to the crook of the handle 16 so that it will normally be spacedshortly from the inside curve of said crook, the space being suiiicientso that when the handle is gripped and the operating arm 26b is actuatedby the fore-linger of the hand grasping the handle 15 there will besutlicient movement of the trigger to operate the valve 21.

The operation of my improved open grip inside trigger inlet valvecontrol for pneumatic tools will be apparent from the foregoingdescription. i

The pneumatic iuid is admitted tothe passageway 16 in the handle bymeans of a flexible pipe or hose (not shown) which is attached to a freeend of the handle in a familiar mannen-the said passageway 16 beingthreaded at its inlet end for that purpose. The valve plug 21 isnormally held in position to close the ports 20, being held in thisposition by means of the spring 22 or b y means of a pneumatic cushionformed by the leakage of the pneumatic fluid about the piston valve pluginto the space between the said valve plug and the closed end plug ofthe valve bushing. Vith the valve plug in this position the trigger 26stands in the position shown in dotted lines in Fig. 1 with itsoperating arm 26b hanging down somewhat away from the crook of thehandle. The handle may be easily gripped without touching the triggerand the tool body may be manipulated as usual to bring the tool carriedby it into the required position. The pressure of the forefinger uponthe operating arm of the trigger will swing the trigger from the dottedposition to the full line position shown in Fig. 1. In this movement thearm 26a of the trigger swings the valve stem to the right (as it appearsin F ig. 1) and moves the valve plug to uncover the ports 20 whereuponthe pneumatic fluid passing through the channels 25il in the valve stemhead piece into the space within the valve bushing about the valve stem24, will thence pass through the ports 20 into the operating valve ofthe tool.

It will be noted that in my improved construction the passage 16 is sodisposed in the handle 16:1 that the supply hose for the pneumatic Huidis attached to a free end of thehandle which is recognized as the mostconvenient place for the attachment of said hose for reason that thehose is out of road of the operator in the use of the tool to which thehandle is attached. It will also be understood as has been pointed outthat since the handle 15 is made in the form of a prolongation of theboss on the end wall of the head 13 and since the passage 16 and thevalve plug 17 are arranged as shown and heretofore described, the head13 may be made as a drop forging with the handle 15 in direct alinementwith the boss 16h. The passageway 16 and the opening for the valvebushing 17 may be then bored from opposite ends of the part comprisingthe continuous boss and handle and the handle may thereafter be bent toproper form as shown in the drawings. This not only sim1 plifies andcheapens the construction but also provides a construction of superiorstrength, viz. a construction made of a drop forging instead of castmetal as has been usual heretofore. ln addition the improvedconstruction and arrangement of the valve passage and of the valvemechanism obvia-tes all transverse passageways in the handle proper andprovides a handle which is of substantially the same breaking strengththroughout. rEhe many advantages of the improved head and handle will bemanifest to lthose familiar with the art.

I claim as my invention:

1. A device of the kind described, comprising a head having an end wallprovided with a lateral extension bent to form an open grip handle, saidhead having a transverse bore and said extension having a lonA gitudinalbore which forms an endwise prolongation of the bore in said head andconstitutes a passageway for the pneumatic fluid, a valve mechanismincluding a valve plug in the said bore of the head, and a triggerfulcrumed in the crook of said handle and having an arm extending intothe said bore of the head to actuate said valve plug.

2. A device of the kind described, comprising a tubular head having anend wall, said end wall, being provided with a boss extendingtransversely thereof and with an extension prolonged beyond said head toform an open grip handle said handle having a longitudinal passagewayfor the pneumatic fluid and said boss having a longitudinal bore whichmeets said passageway7 a valve bushing xed in said boss, a valve plugreciproeable in said bushing, and a trigger fulcrumed in the crook ofsaid handle and having an arm extending through said boss and saidbushing and adapted for the operation of said valve plug.

3. A device of the kind described, comprising a tubular head-having anend wall, said end wall havingI a boss extending transversely thereofand an extension prolonged beyond said head to a crooked handle, saidhandle having a longitudinal passageway for the pneumatic fluid and thesaid boss having a. longitudinal bore which meets said passageway, avalve bushing fixed in said boss and said valve bushing and boss havinga slot adjacent to the crook of the handle, a valve plug reciprocable insaid bushing, a trigger fulcrumed in the crook of said handle and havingan arm extending through the slots in said boss and in said bushing anda head piece for said valve plug provided with a recess and engaged bythe said arm of the trigger.

4. A device of the kind described, cornprising a tubular head having anend wall, said end wall having a boss extending transversely thereof andan extension prolonged beyond said head to a crooked handle, said handlehaving a longitudinal passageway for the pneumatic fluid and the saidboss having a longitudinal bore which meets said passageway, a valvebushing fixed in said boss and said valve bushing and boss having a slotadjacent to the crook of the handle, a valve plug reciprocable in saidbushing, a trigger fulcrumed in the crook of said handle and having anarm extending through the slots in said boss and in said bushing, andsaid head piece being provided with ports connecting the passageway ofsaid handle with the interior of the valve bushing.

A device of the kind described, comprising a. tubular head having an endwall, said end wall having a boss extending transversely thereof and anextension prolonged beyond said head to a crooked handle, said handlehaving a longitudinal passageway for the pneumatic fluid and the saidboss having a longitndinal bore which meets said passageway, a valvebushing fixed in said boss and said valve bushing and boss having a slotadjacent to the crook of the handle, a valve plug reciprocable in saidbushing, a trigger fulcrurned in the crook of said handle and having anarm extending Jthrough the slots in said boss and in said bushing, andsaid head piece having a channel or channels formed parallel to theplane of said recess for connecting the inlet passage in said handlewith the interior of said valve bushing.

6. A handle and an inlet valve control for pneumatic tools, comprising atubular head having an end wall and with a boss and boss extensionarranged transversely of said head, said boss extension being crooked toform an open grip handle and having a longitudinal passageway for thepneumatic fluid, the boss having a longitudinal bore which meets saidpassageway, a valve bushing fixed in said boss, said boss and bushingbeing provided with slots near the crook of said handle, a valve plugreciprocable in said bushing provided with a stem and head piece, saidhead piece having a recess in line with the said slots, a triggerfulcrumed in the crook of said handle and having an arm extendingthrough the said slots and engaged in the recess of said valve stem headpiece, said head piece being provided with channel or channelsconnecting the inlet passage in said handle with the interior .of saidvalve bushing, a supply port in the end hole of said head and said valvebushing having ports in line with said supply port.

In testimony that I claim the foregoing as my invention I airix mysignature in the presence of two witnesses, this 29th day of January A.D. 1916.

MATHEW J. BURKEL. Witnesses:

A. F. MoDowELL, T. H. ALrREDs.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents,

' Washington, D. C.

